Tracking phytoplankton from space in a changing Southern Ocean

The Southern Ocean (SO) is responsible for about half of the global annual uptake of anthropogenic carbon dioxide from the atmosphere. As a remote region, satellite remote sensing is a cost-effective alternative to investigate and gain additional insights into the current knowledge of phytoplankton dynamics in this region. This thesis was set out to investigate ocean colour retrievals and phytoplankton dynamics in the SO and it was developed as a multidisciplinary work using in situ and remote sensing data. The studies developed here have moved forward our knowledge of ocean colour in the SO and contributed to a better understanding of the ocean biogeochemical cycle from the ocean colour perspective by adding new information on the uncertainties in the input terms of primary production models, on the estimation of diatoms abundance and on the variability of diatoms phenology.